Good luck getting that money for them both. What is it, 80K for both on harder difficulties? I've seen Orb of Nothing in shops before. They're not cheap. Still good luck you got that.
Yeah, kinda pricey, playing GR/PD. Hoping my mustache golem will protect me long enough to to be able to use golden ratio for the money. Oh yeah, there was also a Clockwork Bolt-Thrower on the first floor shop too, but the only time I have ever used a crossbow was during the tutorial, so I'm not that interested in that.
Crossbows are good, and not for the reason you think. Throw them on krongs anvuls! get an item that boosts health regen or a stat!
Like Mars said, you don't need any Crossbow-boosting Skill trees or high Dexterity or hell, even a good Crossbow in order for things like Clockwork Drill Bolts, Bolts of Squid, and Bolts of Mass Destruction to be very, very deadly. And even for the most stubborn melee-only character, they make a nice Stat Stick when Krong'd.
as said, crossbows are quite handy to have around. especially by the time corruption blobbies come out. unrelated: marsgreekgod is cheating on spelunky.