Yes, you are able to test some plugin and see how they work even before the purchase.
Demo of products with back-end access:
Hotel Booking - https://hbdemo.getmotopress.com - you can also test there such templates as Villagio, Oceanica, Ciestra, Mountainview, Campterra.
If you purchase the same theme you used at your demo you may request to export your demo data. We'll provide you with SQL file and /uploads folder. We recommend to notify us that you are interested to export demo data beforehand so we could extend your demo not to loose the changes.
HB WooCommerce payments addon - (Demo#1) - https://hbdemo.getmotopress.com
Content Editor - http://mpcedemo.getmotopress.com/
WordPress Slider - https://mpsldemo.getmotopress.com/
Demo of products with Front-End access:
HB Payment Request addon - https://hbdemo.getmotopress.com/payment-request/
HB WooCommerce payments addon - https://hbdemo.getmotopress.com/villagio/
HB Reviews addon - https://hbdemo.getmotopress.com/reviews/
TimeTable - https://hbdemo.getmotopress.com/villagio/
Restaurant Menu - http://mprmdemo.getmotopress.com/