A Broncia S2A would also be a great camera to consider; it has the 6x6 format and waist level finder, like the SQ-AI but it's older, and in a lot of people's opinions, better, because it uses Nikkor Lenses; it's what I started medium format with. I think a used body/lens/back kit will cost around $200 or so on Ebay. I don't know what a Lubitel will cost, but I think the investment in the Bronica or a Mamiya might be better, but my personal preference is for the SLR over the TLR.
Also, considering that the Lubitel isn't considered a very good camera (from what I've heard, I've never used/seen one), you might actually not get a very good experience with it; it may not take very good pictures and it may handle awefully, so it might not be representative to what a nicer TLR or medium format camera would be like.
I think you'd be much better off trying out a Rollifelx TLR, or really anything other than the Lubitel. Ebay prices should be pretty reasonable for any decent analog medium format camera.