How long to paint a 4 bed semi?

I'd agree, there are plenty of cowboys out there. Definitely get someone who is recommended or more preferably, go and see the job that they did and if it us up to the standard that you require. I dont think that it would cost the €5k either. Get a few quotes from some reputable painters.

As for painting it yourself, if you will be happy enough with the job that you think you will do then fair enough. Read up on it first, especially when learning who to treat the wood etc... so that the job is done proper.

There are a lot of small-time good quality painters out there that do a great job and don't charge an arm and a leg either. The only problem is finding them! They are usually very busy too. Ask around and get a few quotes, they may vary a good bit. Id recommend a quote inclusive of paint as they can get the paint at trade price. You will need a lot of it for the whole house. You could also otherwise go to the shop and buy it yourself. Don't go to the likes of woodies etc... for the paint, it will cost you a fortune. Go to crown trade for example. The one in dublin is http://www.homewise.ie/supplier/Dublin/CrownTradeDecoratorCentre/35823/

Im presuming your in dublin

They may even give you advice if you decide to go the diy route. since you will be buying a lot of paint, you can also try and get a discount.