While it might seem like a good deal, I would caution against a cleaner pack for a few reasons.
1. Hermit crabs. Unless those are legit scarlet red hermit crabs they aren't safe with snails. 4 scarlet red hermits usually are almost the price of $20 retail, so I doubt they're scarlet reefs. Most likely dwarf blue hermits, which do grow to be pretty aggressive feeders.
2. Snails. Most likely astreas, which are good algae eaters, but tend to perish once they're on their backs if you don't flip them over. This is more so if one of your hermits finds them on their backs. Possibly wait around for the next round of banded Trochus which readily breeds and people usually bring some as freebies to swaps.
3. Stars. Very few survive in captivity for long term. Fromia sp. and Linkia sp. are usually the price of $20 each and probably the only stars that lasts any length of time. Stay clear of sand sifting stars unless you have an establish sandbed since they consume the microfauna, which they eventually deplete. Hopefully, not chocolate chip stars either, which aren't reef safe.
I would take a look at what kind of algae you're dealing with and then customize your cuc around that. Also, don't load the tank up with them. Their population density is determined by food availability.