Are these good keywords to rank for?

I found a small niche that I think I can profit from.

I found a few different keywords that I would like to target. Here are their exact global monthly search results

Keyword 1- 1,300 GMS
keyword 2- 3,600 GMS
keyword 3- 4,400 GMS
keyword 4- 480 GMS

Keyword 1 and 2 are BUYER keywords with the word sale in them. Here are some stats on the top 3 sites for these two keywords:

#1 position- an ebay listing for the item.
#2 position- A blog with a PR of 1. Only has 4 posts/pages. The keyword is in the blog only 4 times. SEOQUAKE says that this site has 40 internal links and 5 external links (0 no follow).
#3 position- an online shop that sells the item along with other products. PR is 0 and doesn't appear to be targeting this particular keyword. SEOQUAKE says this site has 40 internal links and 4 external links.

Keyword 3 and 4 are very similar. Here are the stats for the top 3 sites for these keywords:

#1 position- a blog with a PR of 2. Does not appear to be targeting this particular keyword at all. Don't see it in the keyword density on SEOQUAKE. SEOQUAKE says this site has 54 internal links and 10 external links (5 no follow).

#2 position- a blog with a PR of 0. Does not appear to be targeting this exact keyword (similar words though). 35 internal links and 12 external links (9 no follow).

#3 position- same website that's in position #2.


Sorry if this is a lot of info but I'm trying to do my best on keyword research before I waste my time building a website for nothing. I think that this niche can be very profitable if I were able to rank in the top 3 position for all 4 of these keywords.

What do you guys think? With the right on page SEO and quality content, do you think it would be relatively easy to rank for these specific keywords?