Hello Pupol!
If the tank is in good estructural shape, I think is worth it, Specially if the acrylic is of a reasonably good thickness (at least .5" thick) or made by a reputable manufacturer. New this tank can cost you almost $2000.
In terms of the material, I would take acrylic over glass any day. You have to be careful about the scratching, but that little care sure beats coming home to a cracked glass tank with all the water on your floor and your animals dead. It happened to me when I had my goldfish. Now days, the biggest glass tank I will use is a 20 gallon. I am sure many will disagree with me and stand by their glass tanks, but personally, I have yet to see or heard of any one's acrylic tank (made with the proper thickness material and by a reputable company) go belly up.
In terms of the hairline scratches, there is a very nice gentleman in sacramento named Marc and his RC handle is MarcDaniels and he has an acrylic refinishing service company and every one who he has worked with has come out very happy with his work. He even works on tanks that are fully stocked and running. At one point, I was going to need his work, but I had to sell the tank to a friend because he had an "emergency" with his glass tank. I did however, got in touch with Marc and he will be the first person I will call when I was to need his work.
If you are seriously thinking about that tank, I would very much encourage you to give Mark a PM or call.
All the best to you!
Maynor
