Those are pretty competitive but don't be discouraged. Yes it could take years, could also just take months if done right. I don't think the latter would happen without paid promotion to help boost organic "word of mouth" type of action that leads to natural linking. You will have to be adding some serious value here and become a disrupter in the niche. Tall order it is.
I wouldn't be able to put a price on this though. People have very large budgets for this industry that varies greatly.
If I were to enter this area I would test the waters with the methods below.
I would hire someone to create me an SEO optimized platform with some basic content, I keep it simple with wordpress and have someone overhaul it to increase its speed and under the hood improvements across the board. Then it would be passed onto a designer that has focus on user experience. I would spend anywhere from $500 to $1000 on this. And usually more as time goes on.
I would hire writers to pump out 750 to 1500 word articles 5 times a week.. Monday-Fri.. $50-$100 per article written by true professionals. You need to hunt them down!
I would invest in infographics and influencers to share those on the weekends Sat & Sunday. This can range in price but I would try and tie this into your articles too compliment them. Lets say $100 for infographic and another $250 for a good influencer.
If you find the right people you can get this done cheaper. You want to provide quality in this niche, it is very important.
After you find some traction and can make improvements based on your users interaction, I would then start promoting it via social networks with paid ads. I would get active in communities where my ideal persona spends most their time, BHW is a good place to start for this Niche obviously