All jetpacks and clothing items are removed weekly, and it may seem difficult to recover them, but there is a way! There is an "item cycle", every Tuesday, there is an item on sale, and every Friday, there is a new or old returned item, which has been happening since the 1.5 Update. Every single cycle takes 22 weeks, but you don't want to wait, there is a special Jetpack Joyride cheat called "Comeback Cheat".
1. Turn on airplane mode
2. Turn off any kind of connection, including Wi-Fi, Bluetooth and NFC (android exclusive)
3. Go to options > Date and Time
4. Set the date backwards, by months for the most effective result.
5. Open Jetpack Joyride
6. Open The Stash
8. Buy anything you can, then return the date to its original setting.
9. Enjoy your stuff. :)
You can get some items on sale.
When the date is set to one of the following, you will get: On 14.5.2013 you will get Rainbow Jetpack on sale (25,000 coins). On 18.6.2013 you will get Super Suit on sale (4,000 coins). On 2.7.2013 you will get Steam Powered Jetpack on sale.
You can also check out official Facebook page for some sale dates.
All pictures were done on Android device.