If you think it's worth it, go for it. For me, I'd never pay more than $20, and I'd still expect good results (my girlfriend's younger sister is awesome at it, never complains, and you have to force her to actually take the cash). I guess it depends how valuable your time is to you. By hand is almost always better than an automatic car wash though.
Personally, I've done well with a simple wash (spray down with water, water + car soap in a bucket, scrub with sponge), dry, and follow-up with a wax paste by hand. It does take a while to apply the wax and buff it back out (especially by hand) but the results are excellent. The two biggest pieces of advice I can give are patience and setting. Make SURE you're washing and especially waxing out of direct sunlight, on a cool surface, and somewhere where a bunch of dust isn't going to get blown onto your car. A shady driveway is fine as long as you don't live on a dry dirt road with a decent amount of traffic.