I'm trying to figure out what you mean by 'low-tech'. I mean compared to a lot of the nano tanks on here I would say my is low-tech.
I bought my 10g tank on Craigslist for $10 and I maid my own DIY CO2 reactor. I have found it to work okay but after reading and also meeting with people here on the forum I am finding more and more things that I can do to my low-tech to I guess upgrade it. I am finding out to have a very balanced amount of CO2 in the tank to get my plants looking healthier than they are now I would have to invest in a CO2 system. I mean after talking to most of the people on here and getting advice from them they all have told me that they started at the same spot that basically we are at now. But I guess have grown, with time, into some pretty techie tanks. I mean I already know now that my next tank I want is going to be an ADA tank with a CO2 system attached and some more expensive things for it. (I just personally like the neatness of the tank and the way it looks compared to an average tank). But I can tell you I would not know that if I did not spend the count less hours on here researching stuff and finding new ways to do things.
I meet with a guy this weekend that ended up just spending the money on a CO2 system just because he didn't what all the work that came with the low tech DIY CO2 system that he made like mine. I mean I'm pretty sure you don't really see that many low tech tanks on this forum because I guess most of the people have grown from that phase that are on here. I got lucky and found this forum when I was just starting out so I would not spend a lot of money doing the wrong thing and, I would have to say most people that are starting out to do a tank really don't spend the time reading for hours a day on arguments on what they should or should not do for their tank.
Although you might not see that many low-tech tanks on this forum does not mean its because everyone went straight for the all decked out tanks. It took them quite some time before they reached that point. And if you had any questions about low-tech tanks I am sure that they will help you on it just as much as they helped me. Of course they will tell you where to go to make a DIY CO2 reactor and it is probably the same site they used when they were making their very own but, then will tell you more efficient ways on how to do something.
I wish I knew what I know now when I was starting because I most likely would have tried to start at a different level. But I'm glad that I didn't because the knowledge that I gained so far is really rewarding to me.
But to fully answer your question I really think 'THaehn' is right. I think that most of the people on this site have made tanks for years and have progressed from low-tech to now what is considered one of the best brands out there for planted tanks ADA.
If you are considering a low-tech to cost a low amount of money mine was pretty cheap and to me looks decent.
Tank: $10 (Craigslist) Came with filter, lighting hood and, thermometer.
Heater: $15 (PetCo)
Substrate: $20 (I had gravel but decided to upgrade soon after joining this forum. You can look at my link above).
DIY CO2 System: ~$15 (Everything included- Sugar/Yeast, Mini filter/power head, and everything else I had in the kitchen).
Driftwood: $10 (PetCo)
Light: $10 (Life-Glo)
Well and I bought a drop checker that just came in today (can do without it would consider this techie but yeah) $25. So in total probably not to bad and I would say it is low-tech.
Check out my thread and it should be an interesting read. It's like a little journey. Hope this helps and just make sure to keep asking questions. Thats what helped me out a lot. People responded to me in like 10min or so.