IKEA, they deliver it to you if you want, other wise any мебельны магазин can do, and cheap is that you do the assembly your self. Other options can be Maxidom, Leroy Merlin, they can also offer you all parts you need to design and make the thing your self, my last table was made from scrap metal (rail from my balcony) and 3 wooden boards + blood, sweat, and tears, around 400 Rub.