There is still an amazing amount of misunderstanding when it comes to the Hwy 1 and the Hwy Ones ... two very distinct and different species ... you combine that with the OP question of comparing them to MIM Fenders, even increases confusion, as there are MANY Fender models that are MIM ... however, IF speaking of MIM Standards (as the $300 price mentioned would suggest), realize that quality can vary within MIM Standards over the years as well ...
If you want to compare a MIM STANDARD to a Highway Series bass, you must first understand the differences in an early edition Hwy 1 ('03-06), and an 'upgraded' Hwy ONE ('06-'11) ... a search of TB should turn up a large amount of reading material on each, although there is probably as much mis-information, as accurate .. after a while you will start to weed through what is what ...
.. a simplified answer to the OP inquiry, the early edition Hwy 1 can be compared to a MIM Standard, as it uses the same neck (headstock adjust) same hardware (the only difference in the bridge is threaded saddles) ... Hwy 1 uses alnico pups, MIM Standard ceramic ... body on Hwy 1 is not routed, MIM Standard is routed ... finish on Hwy 1 is ACRYLIC lacquer, MIM Standard is poly ... the Hwy 1 ('03-'06) carried a list price of about $599, and street price of $479-529 ... MIM Standards about $150 less at the time ...
The Highway ONE, is a different animal than a Hwy 1 ... it compared more to the American Standard (Series) than the MIM Standard, in that it used a heel adjust truss rod neck, and the same graphite support rods as the AmStand, the machine heads are again same as MIM Standard, but the bridge is a Leo Quan BAII, and the body finish is NITROcellulose lacquer ... the Hwy ONE had a street price of $799, and the component value tends to support the additional $$, (even if opinion does not) as the graphite supported, heel adjust neck sells used at a comparative value to an AmStand neck, and considering the $100+ value of the BAII compared to the $25 value of the Hwy 1 vintage bridge ... the used market value of a NITRO body from the Hwy One vs the acrylic finish on a Hwy 1 is also higher ... although most errantly think that the early Hwy 1's had a nitro finish, which is not the case ...
Which is 'better' certainly comes down to preferences .. but, the component value of a Hwy ONE (if bought right) may justify the difference in price over a MIM Standard .. a Hwy 1 early edition, maybe not as much ... there is a difference in opinion of the (Hwy 1) value in the used market, which may be a result of misunderstanding the difference between two models which appear to share the same name ... a common used price for a Hwy One bass (still intact of original components) seems to be about $5-600 range, and an early edition Hwy 1 about $450-500 ... you may see folk spending more than these ranges (Ebay mostly), especially for the early edition Hwy 1, but I wonder if that may be a result of not being aware of the differences between a 1 and ONE. ... so if you evalute based on component value, a current edition ('08+) MIM Standard used at about $3-350 vs a Hwy 1 at around $475-500 vs a Hwy One at around $550+, the Hwy ONE may be a better value than a Hwy 1 (due to neck, bridge and nitro finish value), but most likely all three should retain their purchase value in a resale situation ... But of course the real value comes down to what you like, and can afford ...
.. with all that said, their are some current edition MIM Standards hitting the market sub $300 range, and those may be the best value of all .... it also depends what value you place on having 'Made in USA' on the headstock ... and like all Fenders, each piece really needs to be evaluated on a 'case by case' basis ... both MIM Standards and Hwy 1/One owners have their supporters ...
... JMHO's ...