Reddit mentions of rOtring 1904257 Rapid PRO Mechanical Pencil, 0.7 mm, Matte Black

[Pilot S20] (https://www.amazon.com/Pilot-Mechanical-Pencil-0-5mm-DR5/dp/B001AX7TUU/ref=sr_1_2?s=office-products&ie=UTF8&qid=1520225383&sr=1-2&keywords=pilot+s20&dpID=41ud31tnK4L&preST=_SX300_QL70_&dpSrc=srch): Wooden barrel mechanical pencil. Very high quality pencil and smooth, silky writing experience -- so it's good for long periods of writing (ie. taking notes, math). Nice weighting -- naturally positions itself toward the paper in your hand.

[Faber Castell TK Fine Vario] (https://www.amazon.com/Faber-Castell-Mechanical-Pencil-135500/dp/B000WEAW2K/ref=sr_1_1?s=office-products&ie=UTF8&qid=1520225493&sr=1-1&keywords=faber+castell+tk+fine+vario&dpID=41E%252BerIBzDL&preST=_SY300_QL70_&dpSrc=srch): High quality pencil w/ a mode for soft writing (for taking notes/general writing) as well as a mode for hard writing (drafting, etc.). Has a smooth, flared metal grip as well as an extendable eraser. Absorbs pressure to avoid lead breakage.

[Rotring Rapid Pro] (https://www.amazon.com/rOtring-1904257-Rapid-Mechanical-Pencil/dp/B0055ZUEZQ/ref=sr_1_1?s=office-products&ie=UTF8&qid=1520225819&sr=1-1&keywords=rotring+rapid+pro): Another very high quality pencil. Although this pencil is generally labeled by people as a drafting pencil, it is definitely great for everyday carry. Nicely cut knurled grip -- even if you're sweating, for example, don't really have to keep repositioning hand. Retractable tip, so pocket safe. Weighting is nice as well, heavier than the S20 though. Very durable. Absorbs pressure to avoid lead breakage.

[Caran D'Ache 844] (https://www.amazon.com/Caran-Dache-Infinite-Mechanical-Pencil/dp/B000WFZ7SS/ref=sr_1_3?s=office-products&ie=UTF8&qid=1520226391&sr=1-3&keywords=caran+dache+844&dpID=31BgbaTFd3L&preST=_SY300_QL70_&dpSrc=srch): This pencil has a clean, simple look to it, and writes beautifully. It is also extremely sturdy and the barrel is aluminum, so it has a nice weight to it as well. Not very fatiguing when writing -- good for long periods.

Note: As someone who is currently enrolled in engineering courses, I believe you can't really go wrong when deciding between these. I own each of them and recommend them equally.

i think the rotring 500, it lacks the flamboyant features it's just a pencil, the pentel gg 1000 is good, and uni shift pipe lock since the lead sleeve is retractable.
i wouldn't recommend the 500 if you keep in your pocket because of the lead sleeve doesn't retract and that would mean it can get bent.
if you can get a Rotring rapid pro for 24$ that would probably be better for pocket use.

A few weeks ago the Rotring Rapid Pro, 600 and 800 were going for under $30 on Amazon. You could try those. They're built so well I feel like I could hurt someone by just knocking them on the head with one.

Edit: here you go

rOtring 600 Series Mechanical Pencil, 0.7mm, Black Body (502607) https://www.amazon.com/dp/B001A1POWC/ref=cm_sw_r_cp_apa_i_VCRVCb4Q6AM41

rOtring 1904257 Rapid PRO Mechanical Pencil, 0.7 mm, Matte Black https://www.amazon.com/dp/B0055ZUEZQ/ref=cm_sw_r_cp_apa_i_LDRVCb3JV35SJ

No 800 in 0.7mm under $30 I'm afraid.

Update: After looking at how the Rotring product line has changed since I bought my multipen, I think the Rotring Rapid Pro is a better approximation of what I've been using for so many years.

Whilst looking on amazon, I saw this rapid pro for $16, but it's this cheap due to how long it's going to take to arrive to places like the U.S.A and etc.

https://www.amazon.com/rOtring-1904257-Rapid-Mechanical-Pencil/dp/B0055ZUEZQ/ref=sr_1_6?s=office-products&ie=UTF8&qid=1542918478&sr=1-6&keywords=rotring+mechanical+pencil