Horizon has just come out with a new Spin Bike, the Horizon M4 Indoor Cycle, that I became aware of this summer when I was at the Horizon headquarters (Johnson Fitness in Cottage Grove Wis.) and have just reviewed on this site.
The Horizon M4 Indoor Cycle is a high quality spin bike, from a major manufacturer, that is selling for $349 at Amazon.
The Amazon price is great (if the lowest price is your objective) but the deal that I just found out about is at the Horizon Outlet. They have a sale going on until 11/17 where the Horizon M4 Indoor Cycle is selling for $399 with Free Shipping, a Free 1 Year Extended Warranty (worth $90) and a Free Mat (worth $36).
This gives you a couple of options (go for the absolute lowest price (on the bike alone), or go for the lowest price for the bike and the additional options.
I have included links to the Spin Bike at both Amazon and the Horizon Outlet at Horizon M4 Indoor Cycle Review where you can also read the review on this Indoor Cycle.
As I mentioned the Horizon Outlet deal ends on 11/17 and it is also available for the Horizon RC-30 Recumbent if you are looking for a good deal on a recumbent exercise bike.
The Horizon RC-30 Recumbent is the same price ($399) at Amazon and at the Horizon Outlet so in this case the Horizon Outlet is the best deal.