You can get a HogStretcher from HonestPE with vac cup and silicone sleeve for around $120 + shipping (would get a few silicone sleeves, maybe a few sizes of vac cup if you aren't confident in your measures)
It can't be used immediately post procedure like those you mentioned, but way cheaper (been using mine since 3 months after my first round)
Be sure to look up Perv McSwerve's water trick/method for the vac cup