Tons! Sweets cushions, Kaizen 2.0s, KROM, Ozoras, TKs. KenCo's if you still like shenzhus and raw stripes
To add to this previous list I would also say Sol Kendama has some good stuff for under $40. Their pioneer series looks amazing and I have been hearing good things. Also BLK OG series, I have boughten numerous from Kendama syndicate and after shipping they were like $15! Atlantic Kendamas are also a good pick for under $40. If you go onto Kendama USA they have some really nice KROM kens in the sale section for under $40, some of those will probably be the most bang for your buck, those red oak kendamas are great. Active Kendamas are also great and I feel they don't get a lot of attention, their promods look excellent and they are selling for $30 right now with about $7 or 8 on shipping. I haven't played their promods yet but if they play anything like their standard V2 they are worth it as well. DEAL WITH IT also has a bunch of kendamas that would be right around $40 after shipping and those are definitely worth it. Check out kendamasyndicate.com though, you could probably get two kendamas for about $30 after shipping. Their $10 dama deals are hard to beat. It's almost hard to believe it's real until they arrive in the mail.
Get one of Fujin Kendama's. They have super solid natties you can shred, and their rubberized paint is pretty OP www.fujinkendamas.com
Sol Vibes and Pioneers are great kendamas you can get for under $40. Vibes have a silk paint that can really take a beating and Pioneers have a sticky paint similar to Slaydawg's LOL Clear. Both are really durable, have great tracking and come in a variety of styles to choose from (most Vibes I believe are out of stock right now though). I also recommend the Cook's Customs on Kendama USA's website. The paint is a little tacky out of the box and gets tackier with play. Comes in a wide variety of color ways and honestly they just look so beautiful.
Though I have not tried them (and not particular fond of the colorways) I have only heard really good stuff about the Sol Pioneers so I'll 1-up those. You can get Maple Naked/Party Pelle from Krom right now as well, if you like rubber I think they are about as solid a choice as you can make.
Don't forget DWI for sure! Amazing paint, colorways, kens, and tons of options for under $40. http://dealwithitsf.bigcartel.com/ There might even be a code out right now to get 20% off too! Maybe check their IG.
Definitely a lot of great suggestions for kendamas under $40! I'd check out RWB's; American made, excellent attention to design detail and the best price for a kendama that is made stateside.
The new kaizen 2.0's are under 40$ and you can get 15% off with the code "THANKS16" Or you could cop a pro mod; the teej and colin are my favorite under 40. Www.kendamausa.com
Sol Pioneers are $30 and come with a bag, buttons, and stickers! If you prefer a natural kendama, some of our Sol Flows have been discounted to below $40 as well!
@LacedKendamas are a new company with some amazing kendamas I would check them out! www.lacedkendamas.com
www.analogkendamas.com best kendamas ever! I recommend buying any of they're products that has the et paint! ( extra tacky )
pnw slate @ 21.99, made here in the USA, can't beat it, but you'll need to cop when they drop as they are swooped fast https://pnwdamas.com/
All of the above - great options! My first recommendation is always the new Sweets products though it seems like theyre mostly out of stock right now. Hopefully when they do a new release you can snag one - one of the nicest kendamas you can get out there for a super low price. Otherwise always check for sale updates on various company IGs. KenUSA always has nice sale items year round.