Valve spring tester

Anyone use and have a recommendation for a more affordable valve spring tester? The "good" commercial ones a shop would use are near $1000 new and used versions about half that. I'd be a lot happier around $100-$200 because I'm only using it for my infrequent needs. I have a mill, drill press, and arbor press so the actuator and measuring part is covered, I just need an accurate pressure measuring device. I see some relatively cheap ones on ebay and amazon but haven't seen any positive reviews. I'd rather go without than use something that is off significantly. I prefer to have my own tools when I can, instead of borrowing.