How to get the Sum of all column values in the last row of a resultset without using UNION?
It really depends on your main goal - if it should look 100% like your result in the question above then I am sorry the answer is no.
If you want to get a result with the sum etc. yes there are ways round the union but you might not see the "Total" text.

Here is one solution idea (with less data and columns as I could not extract it from your question).

create table test (year integer, month integer, week integer, cost_carrer char(1),
                    wage_cost decimal(10,2), material_cost decimal (10,2), total_cost decimal(12,2));

insert into test values (2016, 1, 2, '0', 20000.00, 30000.00, 50000.00),
                        (2016, 1, 2, '1', 30000.00, 40000.00, 70000.00),
                        (2016, 1, 2, '2', 25000.00, 35000.00, 60000.00),
                        (2016, 1, 2, '2', 25000.00, 35000.00, 60000.00),
                        (2016, 1, 2, '2', 25000.00, 35000.00, 60000.00);

select year, month, week, cost_carrer, sum(wage_cost), sum(material_cost), sum(total_cost)
 from test
 group by grouping sets ((year, month, week,  cost_carrer), (year, month, week))
 order by year, month, week, cost_carrer


This will return:

YEAR MONTH WEEK COST_CARRER WAGE_COST MATERIAL_COST TOTAL_COST
 ---- ----- ---- ----------- --------- ------------- ----------
 2016     1    2 0            20000.00      30000.00   50000.00
 2016     1    2 1            30000.00      40000.00   70000.00
 2016     1    2 2            75000.00     105000.00  180000.00
 2016     1    2 NULL        125000.00     175000.00  300000.00


And I think this is the "idea" behind your question and example.

Other - even more powerful group by variantions are "group by rollup" and 
"group by cube" which is described here in the documention (with examples)