If you are able to use shipping forwarder bomb and flawless are not too bad on amazon.com I got mine for about 20-25USD each plus the ship forwarder.

Target.com (usa) no longer seema to stock flawless but it was 15usd+shipping to forwarder. So 25 on amazon was ok as it included shipping to forwarder.

Bomb - https://www.amazon.com/dp/B078DN348J/ref=cm_sw_r_cp_awdb_t1_2koNBbAP9RNWG

Flawless - https://www.amazon.com/dp/B077WQDLJN/ref=cm_sw_r_cp_awdb_t1_vmoNBbTVQTQPN

https://www.amazon.com/DropMix-Playlist-Pack-Country-Lucky/dp/B06XKQCHRF/ref=sr_1_1?ie=UTF8&qid=1518214437&sr=8-1&keywords=dropmix+lucky Ships to UK (only two sellers here presently)

https://www.amazon.com/DropMix-Playlist-Pack-Diamond-Exclusive/dp/B077WQDLJN/ref=sr_1_5?ie=UTF8&qid=1518214437&sr=8-5&keywords=dropmix+lucky

58 sellers of this, some do ship to UK just have to hunt.

https://www.amazon.com/DropMix-Playlist-Pack-Bomb-Exclusive/dp/B078DN348J/ref=sr_1_3?ie=UTF8&qid=1518214437&sr=8-3&keywords=dropmix+lucky

21 sellers plus amazon stock this.

I used these guys for series 3 https://www.amazon.com/gp/product/B072XYCV6N/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1 no presently in stock but keep watch!

Currently they are only available through 3rd party resellers

Is that true? I just bought Bomb from Hasbro's account on Amazon (edit: yes, it appears to be true)

https://www.amazon.com/DropMix-Playlist-Pack-Hip-Hop-Bomb/dp/B078DN348J