Thanks for the suggestions. I found a local refurbisher that sells on eBay/Craigslist but offers local pickup to avoid shipping charges. Unfortunately I still need to deal with the 13% tax in Ontario. Here are my choices, from cheapest to most costly depending on my budget (pre-tax):
1. $74 = Lenovo ThinkCentre M58p 6137 Business Small Form Factor Computer Core2Duo 3.0GHz, 4G, 160G, DVD, Windows 10 Home.
Model: SFF 6137 C2D 3.0G/4G/160G/DVD/W10H.
MFT SKU: 6137AU8 Condition: refurbished Grade A. C2D/E8400/3.0G/DDR III/4G/SATA/160G/DVD/W10H MAR/BLACK
2. $124 = Dell OptiPlex GX755 mini-tower computer QuadCore 2.4GHz, 4G, 250G, DVDRW, Windows 10 Home.
Model: TW GX755 QC 2.4G/4G/250G/RW/W10H.
SKU: 392537 Condition: refurbished Grade A. QC/Q660/2.4G/DDR II/4G/SATA/250G/DVDRW/W10H MAR/BLACK
Stock: 1
3. $137 = Dell Precision T3400 Workstation. Model: TW Pre T3400.
SKU: 390277 MFT SKU: DELDKM88 Condition: refurbished Grade A. C2D/E8400/3.0G/8G/SATA/160G/DVD/TOWER/W10H MAR
4. $149 = LENOVO ThinkStation S20 4105 TW.
Model: TW 4105. SKU: 364139 MFT SKU: 4105R9F Condition: refurbished Grade A. QUADXEON/W3550/3.06G/DDR III/8G/SATA/250G/DVDRW/W10P MAR/Black
5. $162 = Lenovo ThinkCentre M90 3245 Small Form Factor i3 3.2GHz, 4G, 250G, DVDRW, Windows 10 Professional.
Model: SFF 3245 i3 3.2G/4G/250G/RW/W10P
SKU: 350455 Condition: refurbished Grade A. I3/3.2G/DDR III/4G/SATA/250G/DVDRW/W10P MAR/Black
6. $162 = Lenovo ThinkCentre M90p 3853 Ultra Small Form Factor USFF i5 3.2GHz, 4G, 250G, DVDRW, Windows 10 Professional.
Model: USFF 3853 i5 3.2G/4G/250G/RW/W10P.
SKU: 348736 MFT SKU: 3853RN9 Condition: refurbished Grade A. I5/650/3.2G/DDR III/4G/SATA/250G/DVDRW/WIN10P MAR/BLACK
Any thoughts, comments? Are these prices ok? I just want to split up the primary Windows partition and install some version of Ubuntu, and plug in a USB WiFi dongle so they can access the internet. I assume all of these desktops have VGA output (or is HDMI output only these days)? If the $74 machine is good enough, I'll just get that, unless you think it's not worth the money and I would get better value from the other machines listed. Thanks for your help!