Looking to strike while the iron is hot, Nokia is apparently working on a low-end, low-cost 4.5-inch smartphone, which could be viewed as the true heir to Lumia 520’s budget-conscious throne.

nokia lumia 520 Mystery Nokia RM 977 handheld crops up, could be jumbo sized Lumia 520 heir

Technically, a crown prince by the name of Lumia 525 is already out and about, but the 4-incher might be brushed away rather easily as it offers only one little upgrade over the 520: double the RAM (1 GB vs. 512 MB).

The mysterious RM-977 on the other hand may up the screen size ante considerably, yet keep costs in tow. Zauba, which is a very trusted and thorough authority that tracks Indian imports and exports, assesses RM-977’s value at $130 (Rs. 7,966).

Sounds like an unbeatable price tag for such a generously sized device, no matter its other specs and features, however one has to take into account potential future added charges. After all, what we’re looking at here is 43 RM-977 units sent to India for “testing and evaluation”, so not exactly phones ready to ship out to end users.

Nokia Lumia 520 2 Mystery Nokia RM 977 handheld crops up, could be jumbo sized Lumia 520 heir

Even so, if Nokia pulls off sub-$200 pricing, the RM-977 has the makings of a blockbuster hit. Again, the spec sheet is fuzzy to say the least, but 1 GB RAM, a dual-core SoC, 1,800 mAh or so battery and 5 MP cam with LED are to be expected at the very least.

As far as timelines go, I reckon it’s no coincidence the handheld is on a testing world tour just as CES 2014 is closing in, so a January ETA sounds about right. Worst case scenario, the RM-977 (Lumia 530? 550?) will go official in February, during or before MWC.

What say you, ladies and gentlemen with an eye for mobile tech? Would you be interested in a low-end, low-cost 4.5-inch Windows Phone? How low should Nokia go on pricing? $200? $180? $150?

Sources: WP Power User, Zauba