Vicelord - Short answer is yeah, it's worth it, even for this recreational rider who only does around 4k miles/year.

If you need new parts, of course you'll pay for them. If you need them, you'll have to get them anyway, and this way you'll only buy them once, instead of trying stuff, maybe getting a refund and trying something else ad infinitum until you finally stumble across the right part. If this LBS has a reputation of pushing customers to buy stuff they don't need simply to drive up their profit margin, then you need to find a different LBS. The guy I went to in Houston is independent, rather than part of a specific shop, so I had few worries in that regard.

Your foot going to sleep is probably a cleat placement issue, based on my own experience.

Good luck in whatever you choose!