So I should probably note that I have not yet completed my stay at this place, but first impressions are VERY good.
I arrived into Kata late in the evening so opted to stay at a different guesthouse paying 450B (more than I would have liked to pay), but it was late so I decided it will do for one night.
Did some online research and Casa E Mare stood out from all the rest! I couldn't really find any accommodation below 450B, however Casa was listed at 425B (ok, not a big saving), but you get a lot more for your money than other places in the same price bracket.
My room is spacious and has a TV, fridge, hot shower (not just a wet room, but a proper separate shower), in room safe, air conditioning, balcony, day bed and is nicely decorated and clean. The attention to detail is impressive....air fresheners strategically placed around the room, towels formed in the shape of swans (not a big fan of that, but is an example of their efforts). Daily housekeeping, and there is even an elevator (don't see that too often in budget places).
Have not tried the Wifi yet, so not sure how well it works. Restaurant is closed at the moment (not sure why) but the Gelato shop is still open. Oh yeah, and there is no pool as mentioned in some write ups. Slight disappointment about that, but I still feel like I found a real bargain.
Rented a motorbike with no hassle. A surprise from what I have come to expect from many rental places across Thailand. Deal is, if you crash it, you take it to a mechanic and pay for the repairs. No need for taking photos or going over the bike with a fine tooth comb noting any scratches and dents. And the best part is, it is only 150B per day. Some places charge between 250B and 300B.
By comparison, the guesthouse I stayed in on the first night for 450B had a bed, cold water shower wet room and was relatively clean...that's about it.
It can be a little difficult to find, but be a smart traveler and write down the address and / or have someone translate it for you. A very friendly guy from Oy Travel and Tourism (near Duke's Sports Bar) gave me a free ride to this place. He too didn't know where it was, but sat down with me, pulled out a map and together we found it quite easily. A friendly guy like this deserves business so maybe go see him if you need to make travel arrangements.
If the internet is not up to speed during your stay, take a few steps outside of the hotel and go to Mamma Pat's Restaurant for some friendly service and good Wifi.