Come on you guys, you can't answer a simple question? You go on about C02 and carbon footprint etc. which is nothing related to the ORIGINAL QUESTION. Go start a new thread, you people are senior members, you know better.

Back to the original question. Yes, Downtube make good bikes. Just do a search on this forum you will see the reviews. The owner is also frequents this board and if you have specific question on any of his models he will answer. Origami is another brand worth looking at, the owner also comes on here frequently. There are a few models from Dahon that are worth looking at. TDS101 also posted a bike that he thought looks good. Another member THOR is a Dahon expert since he is part of the distribution network and he frequents this board but not as much lately.

My take, get something with good gear range because that last 100 feet will not be great if you are struggling. You don't need front shocks, disk brakes for the riding you are doing. You also don't seem to need racks etc. My point is don't pay for something you aren't going to use. Put all the money into the bike itself.

If you have specific question on a model, hopefully someone will answer it without proselytizing their own views on emissions etc. Have a look at the Downtube Mini. It is right at the limit of your budget but it has a lot of bike going for it.