I've been watching flippa listings for a while, looking for a good website to buy and believe I've found something suitable. The site is already ranking well in google but the content and theme on the site is pretty poor. I'm planning to buy it and give it an overhaul with a new theme and upgrading the content. Most pages are about 450 words so I'm planning on making the articles higher quality and pushing the word count closer to 800-1000. I'll be doing this to every page on the site.
My concern is that doing so much drastic work to the site may affect the position in the serps. In theory I would think that if I'm improving quality I should actually see improvements in the SERPs but who knows what google will do.
Does anyone have experience in doing this kind of thing?