I remember when I got my Fuga, saying to one of the shop guys it was the last bike I was ever going to buy (to which he laughed). 2 more bikes later, within 4 years. I bought my steel Merckx because it was a deal I couldn't pass up, and I wanted a beater (it's the world's nicest beater, btw
). Then I decided riding outside all winter was more fun than riding the trainer, so I sold my trainer and bought a winter bike. I use it more than I thought I would, like whenever it's going to be wet out, and whenever I need to carry stuff. It's a great addition to the stable. I do a lot more utilitarian cycling.
But you don't need to/shouldn't go into debt for more bikes. Wait until you have a need for, and the money for, a new bike. You might be surprised what you end up wanting.
'02 Eddy Merckx Fuga, Selle An Atomica
'85 Eddy Merckx Professional, Selle An Atomica
'10 Soma Double Cross DC, Selle An Atomica
Slacker on wheels.