Idea of costs for work to a Victorian cottage please

[NaturalBaby]

We've just had the survey back and have an inevitable list of things that need doing asap. Could you give me a vague idea of how much it would cost - we're in the Midlands.

3 chimney stacks need repair and repointing. Scaffolding won't be straightforward to access them so could be a higher than average expense.
Roof tiles need cleaning, repair and longer term will need to be stripped and retiled - they may need maintenance and inspection annually till they are stripped.

Drains to septic tank need further inspection and cleaning - there's no indication of any issues, they just need servicing.

How much would it cost to connect to mains sewers? We're surprised it hasn't been as it's right next to a newish development so wouldn't be too far to go to connect it. I don't really want the expense of cleaning out a septic tank long term and we're planning on living there for at least 15-20 years.

Doesn't the survey give an indication of expected costs? I was emailed a couple of examples that did... Was it a full structural survey?

It was a Rics building survey, there is no indication of costs because there are a few options - repair the roof in stages but will need total refurbishment long term, get further specialist advice re. damp, joists etc.
All our money will go into buying it, leaving £20k to spend now on bathroom, fencing, patching up a few bits but it will need new windows and further structural work to move walls and re-do part of an extension.

A relative reckons it was costing £600 to empty their septic tank every 2 months for a family of 4 so they got connected to the mains drains. I'm not entirely sure that's very accurate, can anyone give me more realistic prices?

How much would it cost to connect to mains drains, assuming they are fairly close and the property is at the edge of a town (not in the middle of nowhere).

why don't you get the original windows refurbished? will save you a lot of money