There's quite a few out there that cost less than Clonex: Rootech, Dip 'N Grow, EZ-Clone, Olivia's, Earth Juice, etc. But, seeing as how Clonex is the only gel that's ever given me a 100% success rate, I'll stick with it despite the cost.
I know that some of the rooting hormones work well, but... Lately I haven't used anything at all! I do ph the water to 6.0 in the cloner (homemade ez cloner) but that's it with 100% success. It may just be these strains I have? or something else, but I use no powder or gels or solutions of any sort. Usually takes about 3 weeks from mother to being in flower with a 8 inch tall clone and they finish at about 18 inches.
truthfully the dip and grow has given me the best results and the best part is that its prob the cheapest one you mentioned