I bought Maschine Mikro and Komplete 11 because it was on promotion

As you might already know, Native Instruments a.k.a. NI now has a massive promotion of upgrade/update of their products. It is very important not to be confused. Their full versions of products remain the full price. Just upgrade/update versions are on sale right now up to 1st July 2018. See "SAVE ON MASCHINE AND KOMPLETE 11"

As I really wanted to get Komplete 11 for a long time and I learned that Maschine software is useful, I immediately decided to take advantage of the current promotion. I got this set of Maschine Mikro and Komplete 11 Upgrade from an online shop in EU for 369 GBP (420 EUR).

I could get the same kind of sets by buying cheaper Maschine Mikro and software license transfer off eBay, then get Komplete 11 Upgrade offer online. That could save roughly 130 Euro. But, because of potential issues of buying NI products off eBay (read this article if you are thinking to buy Maschine products off ebay or pawn shops alike), I determined that it is safer and cheaper (in terms of time necessary to be spent on potential struggles) to buy a new set.

Besides, I will get a complimentary coupon worth 25 USD for purchases of items on the NI site, which I would not be able to benefit if I was buying a second hand. I hope that I will be able to use the coupon valid for 6 months after activation during the Thanksgiving when companies usually give incredible sales on their products.

However, I must warn that there is yet a risk of buying the gadgets on the budget price right now. NI could be preparing for the next major update on their Komplete 12 and other product lineups. That is a fair risk, given that it probably takes some time till I get used to the new toy.

However my MacBook Pro has not gotten enough disk space available

I was throwing away a lot of files from movies to cache on my 250 GB SSD on my MacBook as if I was a sailor on a sinking ship. A full installation of the Komplete 11 requires roughly 350GB 122GB even though you do not have to install everything. Any case I still need to secure a lot more disk space.

Update (10 June 2018): Komplete 11 Ultimate requires 363GB for a full installation. For Komplete 11, you only need 122GB but it is still a lot for users on SSD.

Since my MacBook Pro is an old one that allows me to install a secondary disk in the optical bay where DVD is, I decided to purchase a hard disk off eBay.

As you might be familiar, the optibay of the newer revision of MacBook Pro 15' early 2011 logic board is not compatible with SATA III disks. So it has to be a SATA II disk or you need to use this product.

Update (9 June 2018): Unfortunately, it appears that users with the later revisions of MacBook Pro 15' early 2011 logic board have problems with SATAII hard disk drive (Toshiba MQ01ABD100) installed on DVD optibay. See this post.

I am waiting for my new hard disk to arrive late next week. My proper installation of the NI software still needs to wait until then...