advice needed with cost of remodeling

[kbaby]

My head is spinning from all the decision making and tbh Dh isn't prepared to discuss it so I need some advice from anyone else.
Sorry if you nod off half way through

We live in a semi detached bungalow, the loft has been partially converted with a dormer at The back and velux windows at The front. Theres 4 bedrooms up there but they are all odd shapes and sizes.
Our room is 10by9
Ds room 7by13
Dd room 10by7
Spare room 6by10
Theres no bathroom.
The stairs are also in our dining room downstairs.

We originally thought that we would extend further into the loft by 5ft and add dormer windows, then remodel the bedrooms to create 3 good size rooms and 1 small showerroom. Also move the stairs to the hall.
This sounded fine until we've had all the quotes, 3 separate companies have quoted between 30-35k. It sounds a lot to me as the majority of the loft is already converted. My dad has now said he thinks its a waste of money as the work we are doing will never increase the value of the house because its remodeling and that we shouldn't do it. However I think we either do it so we have a house we enjoy or move and moving will cost even more.

Dh said he doesn't know, which is no bloody help at all.

What would you do? Or have you done anything similar?

The costs of remodeling will be considerable, almost as if you had no work done in the attic at present. Moving stairs, a new bathroom, taking plumbing upstairs and dormer windows are all costly items. In ball park terms, the quotes seem reasonable.
How much will it cost you to move? Factor in stamp duty estate agents and legal costs. you will have disruption during the building works but also during a house move.
Unless you are a property developer, it matters little about "is it worth it?" It matters more how much you can afford easily and how much it will improve your lifestyle. TBH the removal of stairs from a dining room will add another room to your house; the dormer will add useable square footage to the bedrooms and an upstairs bathroom is a huge advantage in most people's eyes, so if you live in a reasonable family area, then all the improvements seem worthwhile.

Thanks for advice. I can see my fathers view ie its a lot of money for 5ft of space. But to move will cost us £100k to get a house with a smaller downstairs. We looked to move originally but as our house is extended downstairs we couldn't find anything a similar size for what we could afford. Even a 4 bed new house had The upstairs space but a smaller downstairs and that's for over £100k ontop of our current mortgage.
My dad says to move a bathroom upstairs but leave the rest as it is. My issue though is that it still won't be the house we want and The boxroom bedroom dd is in will become tiny as dd grows so we will end up having to move.