I really want to build an 18w LPS fixture but an 18w LPS ballast literally costs almost $300 and there is no way I can afford that. Does anyone know where I can get an 18w sox ballast, ideally under $30? I have a single lamp F40T12 preheat ballast, could I maybe use that somehow?

One of the best alternatives for running 18w LPS is the Fulham Workhorse 3 ballast; testing is Here. For 18w "SOX-E" lamps I found a KTEB-142T electronic ballast (made for 1-42w cfl) is better.. Testing or pics not uploaded for this yet. This ebay item is made with that lamp/ballast combo.

Try 1000bulbs for the ballast kit. $102.45 for the Advance quad-tap
https://www.1000bulbs.com/product/59016/BA-71A0280500D.html

Try 1000bulbs for the ballast kit. $102.45 for the Advance quad-tap
https://www.1000bulbs.com/product/59016/BA-71A0280500D.html

Even that is too expensive for me. I am probably going to use a CFL ballast since after reading about them they work fine. Plus they aren't lossy as bad as the magnetic ballasts are.

I really want to build an 18w LPS fixture but an 18w LPS ballast literally costs almost $300 and there is no way I can afford that. Does anyone know where I can get an 18w sox ballast, ideally under $30? I have a single lamp F40T12 preheat ballast, could I maybe use that somehow?

I know of a place in Edmonton Alberta that has several complete, used Philips Goldeye 18 Watt fixtures model XGC801 120-VAC, all original ballast (might need to be re-varnished), socket, yellowed plastic cover, a tube it might be EOL or it might run another 16,000 hours for $40 to $50 CDN ($30 to $40 USD) they guy seems to base the pricing on the shade yellowing, (I guess he doesn't know about the magic of bug spray) they may also have random screw holes in the back cover, or they might have an aluminum pole mount on them,  I guess they where ceiling mounted ( don't know ) and some were pole mounted, and they might have two 1/8 inch water drain holes drilled in the front cover.

These are not NOS, they are well used outdoor fixtures, but they still function great and with a little effort they will shine bright for another couple of decades easy.. 

Let me know if your interested I can go there and take a few pictures to show you before you decide the guy is pretty cool with me taking them apart in the store before buying them, he'll even let me use his tools, so long as I put them back together before putting them back on the shelf..   

Also if your interested I would be willing to strip it down if all you really want is just the guts to save on postage, or ship them complete and I would be willing to test it to make sure they are working, with a known good tube for at least 48 hours of run time, Let me know, if they are stripped all unwanted parts will end up going to Habitat's Re-store for a second life ... 

If anyone else is interested, I will offer the same deal, I keep it simple, what you pay is what I pay and shipping is what ever Canada post charges and I know the guy had about 15 of them last time I was there, and if the guy gives me a break for buying a few I will give it back to you or mail it to Patrick to help offset the website hosting costs (you decide and assuming Patrick is ok with this)   

Hi Lodge, I'm interested in a used Goldeye. For me it's just to collect the classics. I'm in Montreal. Can you private message me with exact cost? H4R #G# postal code.

I don't know if these are still in stock, but maybe helpful.

https://www.walmart.com/ip/71A0280500D/116430917?wmlspartner=wlpa&selectedSellerId=1103&adid=22222222228000000000&wl0=&wl1=g&wl2=m&wl3=42423897272&wl4=pla-51320962143&wl5=9010778&wl6=&wl7=&wl8=&wl9=pla&wl10=112354604&wl11=online&wl12=116430917&wl13=&veh=sem

I also would be interested in one of those used goldeneyes as well.