I'll answer your question with another question:
If you drop the 3H, what would you hit for a 215 yard shot, or even a 210 or 205 yard shot? Are you comfortable gripping down on your 4-wood to cut distance off of it by that much?
I personally don't see much issue with keeping the 3H in the bag since it isn't actually hurting anything. You say the other alternative is to drop the 4-wood, but why do you feel that you must drop anything at all? It's okay to have a 10 yard gap. If it really concerns you, though, I would think that the best way to go would be to swap from a 4-wood to a 3-wood. This would increase the gap between your 3H and the next longer club without affecting the gap between the 3 and 4 hybrid, which seems to be a number you like better for a gap.
I'm just a little confused why you'd drop down to 13 clubs if the hybrid isn't costing you strokes. I know I find hybrids easier to hit than a wood that I'm trying to hit shorter than usual. I absolutely hate to hit a 3/4 3-wood to cover the cap between a full 3-wood and my 3-iron, but the number for a 3/4 3-wood is such a rare distance that I'd much rather have consistent gaps up through a 3-iron than a big jump from a 4i to a 3H. In my case a 3H would hurt my game, but it doesn't seem like yours is doing you any harm and could be protecting you from an awkward 4 wood shot.
This might not be the most helpful for balls and gloves (though I do see golf ball deals pop up at least once a week), but golfwrx's classified section is a great place to get deals on a lot of stuff. I got my AD-DI shaft there for $130, along with my KBS shafts from 3-LW for another $150 for the set. The AD-DI was used for a week (didn't have a mark) and the KBS shafts clearly only ever had a grip installed on the 7-iron. Good deals there, at least from what I've found, but mostly on clubs and shafts (though they do have golf balls in their classifieds every so often).
The nice part about that is they also have a WTB forum, where you post what you want and people come to you. That's actually what I did for the iron shafts. I posted about what I wanted and I had about 7 responses to choose from within 24 hours, so it's pretty active. For golf balls other than ProV1's that would be your best bet for finding them.
I know how this is going to sound (Oh no, Shane's asking another set make-up/gap analysis question. Ahhhhhhh! Let's run and hide!) But it's a very valid question...
I hit my 3 hybrid pretty well, (I finally stopped pulling it) but I believe it's too close in distance to my 4-wood (225 vs 215). My 4-hybrid is around 200 ish... ( I have a little gap down to the 5-iron... frankly because I just don't hit it much) would I be safe to drop the 3-hybrid?
I thought of carrying both a 5h and a 5i to fix the "gapping issue" but I usually just grip down on the 4h when I'm between the two...
I understand it drops me to 13 clubs; but the other alternative is to drop the 4- wood but that creates too much of a gap.
Things I do when the pace is slow:
Take more time on my shot
Engage in casual conversation
Look around for lost balls
Doodle around, looking nonchalant
Stare at the front group, trying to use force to move them along