I bought a Blacks Octane 1 for £80 a few years ago. Its a copy of a Macpac Microlight. It suffers from having only a one way zip and is missing a peg point halfway along the door and the front guy line gets in the way (but I think the Macpac does the same) however it weighs in at under 1.8kg (or less – its light enough that I haven’t bothered weighing it properly – that is titanium pegs / dyneema guys etc. would make it lighter) and has a good sized porch. It has also stood up to some fierce weather.
The main drawback is the size – as a 1 man tent its quite generous compared to others but moving about is always a bit of a compromise. If you’re always on the move then its fine, but its not really a shelter for taking it easy in bad weather. Also on very cold nights condensation has been a problem, but then the flysheet does come down very low.
If you can afford it go for a lightweight 2 man tent rather than a 1 man tent, you’ll appreciate the extra space on those nights you aren’t in the pub / can’t sit outside.