in an ideal world you would have cable running throughout the house providing wired connections to all the rooms but if you was actually going to put it through the wall to wall jacks it cost £hundreds. The cheap way to do it would be to connect an 8 port switch to a router/shub and run cables from the switch under carpet to each of the rooms and just have a loose cable coming out somewhere in each room. There would be no installation costs and the cable itself is as cheap as chips.
I can not over estimate how important wired connections are. It sounds a silly way of putting it but wired connections give you a 100% pure and unimpeded connection to the router. Basically you'll have a 1gbit lan and you don't have to worry about interference. pings or anything else because all your traffic is moving at "wire speed" and over the short distances you are talking over you'll have a ping of less than 1ms to your router. If there is ever anything wrong with your internet connection you know (for the most part) that it is your outside connection to VM that is the issue and not something in the house. That being said, there are still lots of things going on like peak time congestion which I mentioned earlier which can still prevent you from getting 30mbits all the time.
If you wanted to go with plan b for as cheap as possible then you would buy a good 8 port switch (£40), you would need to keep the shub in router mode (not ideal) and run the cables round the house as I have suggested.
If you wanted to do it properly (which would be worth it in the long run) then you would buy a new router and switch, put the shub in modem mode and connect it to the new router. Attach the new switch to the new router and run cable round the house. Upgrade the package to 100mbits and allow everyone to either use wired connections for static devices like pcs and you still have the new super new wireless for tablets/mobiles etc.
It sounds like a bit of a faff but it is like putting a skeleton in somebody's body; once it is in that is it and it will continue to benefit you everyday in so many ways for years to come. I don't expect your landlord will go for it at all but in case you were wondering I would say £140 for super duper new router and switch and £70 for 7 x 50m cat5e (
here)
The important thing to emphasise and what I am sure won't be appreciated at all is the fact that you are putting the network infrastructure (albeit minimally) in place to provide fast and reliable internet access throughout the house which is going to require no maintenance and will continue to work for many years to come. The wan to lan throughout on routers these days far surpasses what VM are going to be able to give you for the next 5 years or so so you/he won't have to worry about replacing anything. It is a sound investment in performance and enhancing your quality of life and once it is done that is it; it is a one time charge.
If you want a router for the £50 mark go for either of the ac1200 variants on those links.