I have never needed to look for one, but there should be cheaper 3rd party options, no? I agree that £45 seems a bit steep.SD card really annoys me. I use my camera a lot, but don't want to shell out the £45 apple are asking for one. So I just plug my camera into the USB cable, which I then attach the USB-A dongle to, which I then connect to the MacBook.....
Most of these can be replaced by a single USB-C minidock (which has HDMI out and card readers). For Display Port you don't need an adapter, as its natively provided by USB-C (only need an appropriate cable, although its true that these cables are fairly rare and you likely won't find them on site). I'd suggest you try a minidock though, it could replace most of the adapters you are carrying.2 x USB-C to USB-A ( USB BD writer and a clients USB drive at minimum )
1 x USB-C to digital Multiport ( power cable in, HDMI Out and an external drive that has a fixed cable )
1 x USB-C to Display Port to hook to a color grading external screen.
1 x USB-C to SD card reader. or at times another C to A adaptor and a CF card reader.
these 4 I have plugged in quite regularly at client sites, now sometimes I also need:
1 x USB-C hub because I ran out of ports
1 x USB-C to VGA ... because lots of old projectors still out there.
1 x USB-C to LAN ... some places don't let you on wifi
I purchased the 2016 unit to see how well it might work in my workflow, and as an experiment so I no longer needed a high power hackintosh laptop for certain things, its power is fine, its connectivity I find however is an issue at this point in time. and have gone back to a larger machine with an OSX-VM
I got lazy .... needed the portability and ports so have gone back to using a true PCIE dock which clips to the bottom of a couple of my laptops for that kind of work ( its bloody nice to daisy chain 6 external displays off of a pair of DP ports ). I do wish someone would come out with a GOOD flat plate base dock/ extended battery for the 15" but I cant have everything unless I can convince my husband to build and 3D print one.If you have to connect a lot of peripherals then notebooks aren't very suited devices because they have a limited amount of ports. The amount of cables and adapters you are carrying with your MBP sounds very familiar to me. I did that at school and later at work as well. Alas, that's what you get when you're a technician. You have to be able to connect every possible exotic piece of hardware. Luckily this has improved since USB, Firewire and Thunderbolt (read: less proprietary stuff).
That problem is not going away as I've seen demonstrated today and many times in the past. People do forget their charger sometimes and in those cases it seems to be rather difficult to find a replacement. Either because they are hard to find or because someone else needs to use their own just as badly or both.If I forget to bring any adapter or even the charger, I am generally ****ed because I can't borrow one from anyone else as in most cases others are using an older model. It's a problem that goes away eventually but at the moment it is annoying to have to worry about it when on the previous models this was a non-issue, I could expect to connect that one HDMI or USB port when needed.