The Cable Company is an on-line retailer of a lot of brands of "audiophile" cables. They will let you demo IC's through their "lending library". You basically give them a refundable deposit, they ship you the IC you want to demo, you get two weekends to decide whether it is worth the money, and if not, you send it back. You only pay return shipping. They refund the deposit.
There are also some smaller cable companies that offer 30-day or 60-day trial periods (Audio Arts, Morrow, Gabriel Gold). You buy the cable and if you don't like it you send it back before the trial period expires for a refund.
Of course, you could just buy everything from Blue Jeans Cable...probably the wise choice if your system isn't uber high-end and funds are limited.
And, if you want to go with IC's sold by the Cable Company that you have demo'd and like, do yourself a favor and try to find them used on Audiogon rather than paying full retail price. In general, used IC's go for 25%-50% of the original retail price.