For some "money pages" on our site, we need to take every opportunity to earn money. If you are not concerned about the rank of this specific page, don't be afraid to put an affiliate link near the beginning.
In my Wealthy Affiliate review, you can see that I have two links at the very top of the page. These get the most clicks of any link on the page.
Don't get too excited though, as they also have the lowest conversion rate of any link on the page. Links at the top of the page generally get more clicks, but fewer sales. Think about it - these are clicks from people that do not fully understand what they are purchasing yet. You have to consider, "How many sales and I losing to a non-converted click by placing a link at the top of the page?"Experiment and see what happens. At the end of the day, you need to look at your bottom line. It doesn't matter if your conversion rate sucks as long as you are making the most money possible from a page.
The example above is specific to my WA review, but this concept can easily be applied to other product reviews. WP Review and WP Product Review are two free plugins that can easily create a "snapshot" of the product you are reviewing. They include an option to add an affiliate link.
You can also just do something simple like adding a few lines of text with the information you want to display. You can make stars or other custom images to display your personal rating (get creative!), or have a "fill in the blank" code you paste into every post. If you can't create images or do code for yourself, this can be outsourced at oDesk or a similar website.