Replacing Hall and Kitchen Flooring

Belcheee

Hi, we currently have glossy black tiles in the hallway, kitchen and conservatory. They are about 20 years old but pretty solid still - a couple of loose ones and one or two cracked. The grout lines are very thin and not very deep either.
We are looking to change them to LVT ideally, although re-tiling is a consideration too given the costs we're being quoted. The whole area comes to around 30m2.

I was hoping we could lay click LVT on top of the tiles but flooring companies and also friends who have done it say it doesn't work very well, there are gaps under the new flooring which means it flexes/bounces. Dryback (glue down) LVT has also not been suggested due to slight variations (2-3mm) between some tiles.
There is also a peak in the floor in the centre of the kitchen, where an old extension was done, so from the peak down to kitchen units is about 10-15mm height difference from level.

The best way to do it is to get all the tiles up and screed the floor, basically starting from scratch, then we have a perfectly flat floor to work from.
The problems I have with that are around the cost (probably 800-1000 to screed based on the area), the upheaval - we have a fridge and cooker that will need moving out of the way, we're living in the house so will need the kitchen and hallway, and also we don't want to screed all the way to the kitchen walls as there are fitted units and probably another 5-10m2 of space under those that we don't want to pay to screed when we don't see or use it.
We're not too bothered about having to lift the tiles and grout, that will just take time but we can handle that.

Everything I see online suggests screeding is generally done when a house or extension is new or is being completely gutted. It doesn't seem feasible to me to go through all the upheaval and cost when we have decent tiles down.

I'm just after advice on any other options. Screeding and starting from scratch is obviously the sensible way to do it but we also need to be practical and it seems like overkill at the same time.
I wouldn't want to take on screeding myself. For one thing I don't think "screeding" is even a word, according to my spellcheck, so that shows how DIY I am..

Does anyone else have experiences of laying LVT or even laminate on top of existing tiles? Or tiling on an unperfect floor (i.e. one that had old tiles on but hasn't been screeded fresh)?

I should add that we are not 100% committed to staying in the house long term, likely we'll be here 4-5 years or so yet but past that we're not sure.

Any advice appreciated, cheers.

Doozergirl

If you lay tiles, it won't need screeding at all, it will just need scraping back so that you have a good solid surface with as little variation as possible. 

For LVT, you're looking at self levelling compound if the floor isn't too bad once the tiles are up.   You could self level over your existing tiles but you're then relying on the tiles to stay solid underneath and LVT is not a small investment to only find it goes wrong.  

You do want it as good as you can get it, but you can feather out and smooth any irregularities in the floor so that they're not quite as noticeable.   Tiles will be more forgiving than LVT will, but you could get away with a bit of a slope at thresholds etc.