While the investing hordes are finally beginning to clamor for gold exposure some nine years into this secular bull market for precious metals, many trample right past a more affordable and more alluring alternative to get there: silver.

In the midst of a gold overload, silver is the overlooked bargain that savvy Fools will discover before the spotlight of popular interest arrives there in turn. The progression is predictable: Once gold bullion rises out of the reach of many retail investors, silver will garner more of that spotlight that is now so intently focused on gold. History reveals this dynamic as a key basis for the slingshot effect that I described back in April, and it is the very derivation of silver's colloquial nickname: "poor man's gold."

I have carefully spelled out the fundamental rationale behind my $2,000 price target for gold, but the time has come to explain why I believe silver will reach at least $50 per ounce before this bull market has run its course.

A simple matter of ratios
In case you were wondering, my price target has nothing to do with the historic price spike in 1980 that saw silver trade just below $50 for little more than a heartbeat. Since the Hunt Brothers famously spurred speculative buying with a market-cornering position in bullion, and since the nature of our global fiscal predicament differs materially from the challenges faced at that time, comparisons to 1980 provide little insight to those wrapping their heads around gold and silver.

Actually, my price target is derived from the metal's relationship with gold, and is therefore an extension of the same slingshot effect. When gold reaches $2,000 -- an expectation for which I have provided ample support -- a corresponding $50 price tag for silver equates to a conservative ratio of 40:1 between the two. After topping out at around 80:1 during last year's brutal correction, the ratio presently stands at 64:1. Experienced silver investors will recall that when gold first broke through the $1,000 barrier in March 2008, silver had surpassed $20 for a ratio that briefly slid below 50:1. I declared silver a relative bargain at the time, which should give you an indication of just how cheap I consider the sub-$20 silver that we have right now.

For further context regarding ratios, consider that the relative scarcity of gold and silver contained within the Earth's crust yields a ratio of 15:1. This geological relationship shaped the price structure between the two metals for centuries, resulting in a long-term historical price ratio that remained beneath 20:1 essentially until the United States abandoned its bimetallic monetary standard in 1873.

A simple matter of supply and demand
Investors resistant to the notion of gold as a viable asset class often point to a perceived lack of utility as a source of their discomfort. Although I consider gold's monetary utility reason enough to invest, the other precious metal does indeed boast the kind of industrial uses that a pragmatic Fool demands.

Silver is the most conductive of all metals (including copper), and it remains conductive even when tarnished. Silver is an effective thermal conductor, and it also reflects light more effectively than any other element. The metal's anti-microbial and antibacterial properties are well documented. In most industrial applications, silver can not be substituted, which implies relatively stable demand even as prices rise. As a result of these and other unique properties, silver is in constant demand for applications from electronics to water purifiers. Although demand for silver from the photography industry is in decline, that decline is more than offset by fresh demand from the worldwide craze for handheld devices … which Coeur d'Alene Mines (NYSE:CDE) CEO Dennis Wheeler estimates at 200 million tons annually.

Shifting to supply, we find another monumental source of bullish sentiment among serious silver investors. As it turns out, the world has experienced a structural deficit in the silver supply for each of the past 18 years, and the above-ground supply has dwindled accordingly. The United States has entirely disposed of its once-mighty strategic silver stockpile, and silver guru David Morgan estimated in 2006 that the entire above-ground supply of silver worldwide reached a paltry 500 million ounces. At today's prices, that equates to a market value of just $9.5 billion! If even a minute fraction of the investment demand presently targeting gold shifts to silver in the future, I expect this scarcity of physical supply to exert enormous upward pressure on silver prices.

Simple choices for your portfolio
According to a recent non-scientific Motley Poll, some 66% of you expect silver to outperform gold as we progress further into this precious metals bull market.

Another recent poll produced results that surprised this Fool. Among a list of quality primary silver producers, Hecla Mining (NYSE:HL) garnered a full 35% of your votes (463 out of 1,317 votes cast) for your favorite name in silver. While Hecla's Greens Creek mine is a treasure trove, Silver Wheaton (NYSE:SLW) offers a unique exposure to essentially fixed production costs. Silver Standard Resources (NASDAQ:SSRI) holds truly massive reserves, while I feel Pan American Silver (NASDAQ:PAAS) and Silvercorp Metals (NYSE:SVM) deserve Foolish consideration as well.

There you have it, Fools. This is as close as I can come to an abbreviated synopsis of my investment rationale for silver and the miners that produce it. It's time for you to share your thoughts on the matter using the comments section below, and by joining the CAPS community to craft your own model portfolio with silver exposure.

Fool contributor Christopher Barker carries a silver coin that reads: "Honest value never fails." He can be found blogging actively and acting Foolishly in the CAPS community under the username TMFSinchiruna. His silverminer CAPS portfolio has achieved 94% accuracy. He tweets. He owns shares of Coeur d'Alene Mines, Hecla Mining, Pan American Silver, Silver Standard Resources, Silvercorp Metals and Silver Wheaton. The Motley Fool's disclosure policy is 0.999 pure.