Suggestions for reliable light weight tent

Check an MEC store, across Canada. Their website shows a two person tent sold under their own brand name for 200 CAD, weight 2.5 kg. I have not used it, but the website also shows customer reviews.

Google MSR Huba Huba or Macpac Microlite.
If you choose one with a detachable fly this will allow for ulta lightweight summer trips.

I second the MEC stores in Canada.
The Tarn 2 and 3 are a classic. Bullet proof, freestanding, and good value

I know you mentioned the cost limit but just as a reference point, check the Hilleberg Anjan 2 at 1.8kg. I mostly stay in hotels but in some parts of the world where I get caught out I need a tent so I carry this and only use it about once a month. So it is pretty much dead weight and the lighter the better. It is an excellent tent too.

I'd second the Macpac Microlite.

Mine's around twenty years old now and has been used on backpacking trips during my days as an instructor so it was on my back all of the time. It's stood up to some pretty stormy conditions here in the UK and come up smiling.

Hilleberg also have a very good reputation too on this side of the pond.

Can suggest Vaude Hogan Ultralight. Only positive experiences since 2009. Good space/weight/rainproof combo. Have used it even with snow.
Probably side-opening is a miss, but otherwise very good alternative to MSR Hubba, which is in the similar range.

I've had good experiences with my Tarptent Scarp 1.

There are two things I particularly like about it from the point of view of bike touring:

1. You have the option of making it freestanding or not, depending on how important that is relative to weight.
2. It has two decent sized vestibules, which I find great for keeping bags dry on one side, while having clear exit (or cooking, etc) on the other side).

I also like that its high enough to sit up in - so its quite comfortable if you are stuck in it through bad weather, etc.

I use a Hilleberg Akto at 1.6 kg but there is also the Nordisk Telemark at 800g but its quite over your spending limit. Specialist equipment costs.

http://www.nordisk.eu/bred/products/tents/tents-detail/type/tents/categories/telemark-1/product_model/ulw/

Any observation on the Hubba Hubba durability? I've read a few reviews that say it's not very durable, although I don`t know how they can say this by looking at a brand new tent.