A few comments on the Portuguese part:
- coffee for 1,20? That's a rip-off by Portuguese standard! Standard price is 0,60, some places still sell coffee for 0,50 or 0,55, anything above 0,80 is considered expensive.
- re ATMs - you can get maximum 200 euros per one transaction and 400 euros per day (so you can just take 200 and another 200 right next).
- if you eat out at simple places where the locals eat and take dishes of the day (pratos do dia), you can spend as little as 18-25 euros per couple, plenty of wine and coffee included. A single dish is anything between 6 and 10 euros, house wine (vinho de la casa) comes for as little 1,50-2,50 euros for a 0,5 l jug. Some places offer set meals - soup, a dish of your choice, olives & bread, a drink (wine or beer included), dessert and cafe for as little as 8 euros total per person. However, to find such bargains you would need to wander a bit off the tourist trail.


Just checked the receipts - only one coffee at 50 cents, others 0.70, 1.20 or 1.50, but that was for cafe duplo.
Coffee here in England yesterday was £1.95 each in a small local cafe.

OK, now I understand. Cafe duplo costs usually just double the price of a single coffee.
I have paid 1,20 or so for a single coffee a couple of times - on Lisbon airport and in a few very touristy places (beach bar in Cascais, centre of Sintra). Otherwise it is always 0,50-0,70, sometimes 0,80.
I have a lot of comparative material, as I have lived in Lisbon for half a year and take several coffees a day :-)

I'd be there for a coffee or a Sagres or two at the drop of a hat!
The work for a return visit has already been done, but the trip has been put on hold as I'm setting up a new writing business at the moment, hence the keeping of the receipts from last year in readiness for doing a few pieces on what was a very enjoyable time in Lisbon, Evora, Tavira, Sagres and Lagos last September!
How much £ for my 30 day holiday to Spain and Portugal?
None, as you will have to use Euro

OP is based here in the UK so the overall budget probably depends on pounds sterling and various elements may have to be paid for in pounds sterling. Any price information gleaned from posts on here or from guidebooks that are referred to in Euros can then be converted into pounds sterling to see whether the costs are in line with the OP's budget...