I got a quote from a vendor from AliExpress for my machine that seems pretty reasonable. I'm not sure what precision the screws are or if they come with the necessary nuts or not (I'm not ready to order mine yet, so I haven't asked those questions yet), but you might contact him and get some info. I ordered some linear rails, 20mm with the bearing blocks and got them within a week from China. He is also very good at getting back to you. Usually got back to me within 24 hrs.
Here is what he quoted me for ball screws:
32mm Dia, Pitch 5 mm
2x Length 1524mm Price $167
1x Length 1830mm Price $95
1x Length 710mm Price $54
25mm Dia, Pitch 5mm
2x Length 1524mm Price $105
1x Length 1830mm Price $59
1x Length 710mm Price 36
32mm Dia, Pitch 10 mm
2x Length 1524mm Price $175
1x Length 1830mm Price $102
1x Length 710mm Price 59
25mm Dia, Pitch 10 mm
2x Length 1524mm Price $110
1x Length 1830mm Price $61
1x Length 710mm Price $38
The website is AliExpress.com. The vendor that I used was J&G Hardware Supermarket. I'm not sure how to search for vendors. I'm at work and the website is blocked for me.
The particular person that I talked to was "Jack GU" and his personal email is "
[email protected]"
In case you still need linear bearings, here is what he quoted for me:
SBR20 Rails
2x Length 610mm
2x Length 1220mm
2x Legnth 1524mm
12x SBR20UU Carriages
Total price $353 USD (including the shipping cost to USA)
They shipped out on a Monday from China, and I got them on the following Friday. The packaging was less than desired, but I didn't see any major damage (small ding on a corner or two) and all the lengths were over what I requested by ~1/16 - ~1/8 as opposed to under.
Hope this helps.