SMD features pretty heavily in my CNC machines.  Most of my solenoids are made by them.  Pretty solid too - my mill is 37 years old now and all of the SMD parts are original and in daily use.

Marlin P. Jones has a selection of surplus actuators at hacker prices:

https://www.mpja.com//search_results.asp?q=pneumatic

I've never ordered from SurplusCenter, but they have some good items at hacker prices as well:

https://www.surpluscenter.com/shop.axd/Search?keywords=pneumatic

You can build a working "proof of concept" demo at hacker prices, then look into real professional devices from McMaster carr.

Good luck!

I have dealt with Surplus Center a number of times Their packing can be a little rough but the items match the descriptions and I have been happy with the results.

Regarding manufacturers for pneumatics, the one I think of most often is Bimba (bimba.com)

I've used various cylinders and control valves from them over the years, though I'm not particularly familiar with pneumatics other than just as an adjunct to other projects at my last job.

Pneumatic and hydraulic actuators are really only used in scenarios requiring a lot of torque at high speed.  If you don't need /both/ of those then you can easily go with an electrically driven linear actuator which can be fast or high torque but rarely both.

Anyway, here's a good place to start looking that will let you see the price of what you are interested in: https://www.mcmaster.com/pneumatic-actuators/