I would suggest a Titan 440 or Graco 390/395(not the Magnum sub-brand) as the as the lowest I would go if purchasing--AirlessCo is good too! You can find these online sometimes in the $400-500 range.

The cheaper sprayers will not hold up or give you pressure to spay latex without lion-tailing. Stay away from the Home Depot or Lowe's consumer oriented sprayers at all costs.

Buy a decent sprayer, clean it exceedingly well after use, store it with premixed automotive antifreeze inside, and it will last you 25+ years....

If you choose not to afford these options, I would rent a sprayer.

If you want to do cabinets or fine detail work, an airless is not the tool. You want an HVLP or Air Assisted Airless. Astro HVLP guns are a good, low cost copies of the German Sata brand(expired patent). They are about $125 on eBay. I actually have two Astro guns: one for automotive primer and one for polyurethane.