I'm sorry if this comes across as too pushy, but pole wear is an excellent idea for any studio.
I understand that all of those things cost money, but in all reality, I feel like you would make more money if you bought things in advanced. I had a studio owner tell me the other day that she had a group of rock climbers come in to buy dry hands because REI and Dicks were closed that late :P
Aside from that, actually being able to purchase clothing (OR, SHOE RENTALS!) on the spot is heavy peer pressure and will keep people in your studio. I have avoided to going to studios before because I didn't leave my pole shorts in the car that day and was wearing pants or whatever. Whenever I get "shorts envy" (Bad Kitty Brazillians criss crossers, I'm lookin' at you.) I feel the need to ATLEAST try the pair on. And if I like them, I will buy them on the spot regardless of how broke I am. Because pole is an investment. Plus, I can write it off on my taxes :P
Pre-paid orders for large items such as poles make sense as a studio. But clothing? I can do that by myself in the comfort of my own home (even though I'm pretty sure it's super obvious I'm a medium to large.) Not only that, but as the studio owner since you are ALLOWING people to try the wares before they buy them (or not, as you are the owner, you make the rules), you have the ability to chose to mark up the price. After all, you paid for shipping and handling and whatnot. So a markup of $5-$7 per piece of clothing, especially if you order in bulk, is a huge profit to you and not so big of a markup for us. Not only that, but some websites (Veena and BKEW) only accept PayPal. And paypal is a bitch and half for some of us to work with. Just...take my cash, take all of my cash!
https://www.dryhands.com/order.php <-- according to the website, dry hands is only SIX DOLLARS a bottle. Have I ever seen Dry Hands in a studio for less than $6? Nope. Infact, before I looked I assumed it was atleast $10/bottle. The cheapest I've seen is $10 ($5 mark up) and the most expensive I've seen was $17.50 (I think there's a reason that studio hasn't been doing well, but I just can't put my finger on it...) I currently pay $13.50 just to have it on hand because I'm impatient and don't want to wait for shipping when I forget to order it from a website I normally order clothes from.
Pole is an investment for owners and dancers alike, but aside from physical pay back, you can make a dollar as well. But there are things that you would have to spend money for in advance.
Little things that wouldn't cost you that much money are, as Sassy mentioned, toiletrees. I want to kiss a woman whenever she gives me a tampon when that unexpected visit from Mother Nature comes a knockin. It saves a lot of embaressement, "DOES ANYONE HAVE A TAMPON :( "
Medium sized things, like furniture
Larger things are floor length mirrors and adjustable lighting. I prefer a more darker, comfy atmosphere when I am training. When I am recording, however, I need the lights. Some studios are so dark that you can't even see the silhoette when you record, making recording next to useless.
But more than anything, listening to your students is what will make YOUR studio grow. A suggestion box is a very small price to pay for YOUR students, who might have different needs and expectations than those of us on Studio Veena. Hope this helps :3