When I do a search on rightmove for flats in Glasgow West under £600, I receive plenty of results, Beccarose. What type of search parameters are you using? Now, whether they are in good locations around shops, I'm not sure. I'm only familiar with the West End, near the Uni of Glasgow, and with the city centre where all the shops are.
We're hoping to get a 2bd flat, as my OH is studying at uni and we don't want a desk in the bedroom (which could disrupt my sleeping) or in the living room (which would prevent me from watching tv).
I am aware of the additional costs of council tax, which is why I wanted to keep the rent to around the £550 mark. I was thinking about allocating £750 to rent/council tax, but we still have to budget enough money for groceries/leccy/transpo costs/etc, and to send money back to the US for my student loans and also have enough to pay for his classes. It's all starting to add up, and not knowing how long it will take for me to find a job, we have to find a way to live off his income alone. Hence trying to keep rent around that level, until I have a job.
But if we can't use that 25% rule, then we might be tighter on things than I thought.