The tighter your screens are, the brighter your prints will be. The tighter your screens are, the less squeegee pressure is required to print properly. How much pressure do you think it takes to push ink through a screen anyway?
Tight screens improve registration by reducing or preventing “screen roll”. Screen roll is the pressure wave of mesh that rolls up in front of the squeegee much like a wave in the ocean. Tight screens allow more ink to sit “on top” of the garment where it belongs rather than being smashed through the weave down to the platen (which helps fend off sublimation in more ways than one), reduces the need for massive squeegee pressure (which most printers apply), and finally lets you set your squeegee angle at the proper upright position of 65 to 75 degrees. The proper squeegee angle allows you to efficiently use the business end of the blade (the edge).
Frankly, using less expensive frames that do not achieve higher tensions (over 25 newtons) are costing you money, not saving it.
“Time is money, so don’t waste either”.