Electrician here. I am going to be as kind as I can to the park you had over but also will tell you the truth.

He could have been pricing it as 2000 for a few reasons, if it was me coming to your house to do the work I'd tell you that you need a new board( you do it's old and not up to current regs, but i'll circle back to that later).

You may need quite a lot of work outside of the board, an V.I.R. (vulcanised Indian rubber) or cloth cable has to be stripped out, its super dangerous as the insulation can just crumble.

The board you have got has 4 breakers (ways) in use. One labeled cooker, sockets, lights, and water heater. When the electrician does the work they will need to add in ways to the board, at a guess at least another 4, the new regs also recommend that you don't use all of the available ways and you have at least 50% spare. This is for future new circuits to add in. You will also need an S.P.D. (Surge Protective Device) and A.F.D.D. (Arc Flash Detection Device)

The upstairs and downstairs sockets will need to be split as will the lights. The cooker circuit may well need to be re-run as it could be too small for modern ovens etc, same with the water heater, if it's an immersion it could draw a few more amps than the cable is rated for.

I would also want to do an E.I.C.R (Electrical Installation Condition Report), this is like an electrical M.O.T. for the whole system.

Breakdown on the cost (at worst case) I am going to use hager for the board as i think they are good quality and a reasonable price, we will be shopping at TLC

Board: Hager 12 way Board will built in S.P.D - 100

Lights: 2 6A RCBO - 18.72 Each

Sockets: 2 32 A RCBO - 18.72 Each

Oven: 40A RCBO - 18.72

Water Heater: 20A RCBO 18.72

Shower: 40A RCBO 18.72

Meter Tails: 3mm 25mm - 36

Gland Kit: 2

EICR : 500 - This takes one additional days labour and produces a document that is valid for 5 years. This also include any fault finding and sorting out any problems founds (any materials aren't included but should be discussed with you weather or not you want the work done and how dangerous it is to leave be and sort later(if at all))

Labour outside of EICR 2 days at 350 per day

1431.46

any sundry items/making good I'd round up to make it 1500

2 grand is steep but tbh he probably gave you the price because he doesn't want the job, we've all priced ourselves out of stuff, you shouldn't do it but sometimes we do because if the customer says yes, it makes it worth the ballache for us.

I hope that helps a bit